Mechanism for the interconversion of reciprocating and rotary motion



A. G. M. MICHELL.

MECHANISM FOR THE INTERCONVERSION 0F RECIPROCATING AND ROTARY MOTION.

APPLICATION FILED JUNEH, 191s. RENEWED APR. 28, 1921.

1 ,409,057. Patented Mar- 7, 1922.

3 SHEETSSHEET 1.

WWW?" I j A. G. M. MICHELL.

MECHANISM FOR THE I'NTERCONVERSION 0F RECIPROCATING AND ROTARY MOTION. APPLICATION FILED JUNE 11, 191B. RE NEWED APR. 28. 1921.

1 ,409,057, Patented Mar. 7, 1922.

3 SHEETS-SHEET 2.

282 A 6 59 25 A 2* 25 r 4 46- $4 22521:. AHA

m zegaseks Z7za'672i07 A. G. M. MICHELL. MECHANISM FOR THE INTERCONVERSION OF RECIPROCATING AND ROTARY MOTION.

APPLICATION FILED JUNE II, 1918. RENEWED APR. 28. I92I.

1,409,057 Patented Mar. 7, 1922.

3 $HEETSSHEET 3.

M %M/% a Wrmg HEISSUED I "UNITED STATES PATENT OFFICE.

ANTHONY GEORGE MALDON' MIGHELL, F MELBOURNE, VICTORIA, AUSTRALIA.

MECHANISM FOR THE IN TERGON VERSION OF REGIPROCATING AN'D Application filed June 11, 1918, Serial No. 239,384..

To all whom it miig concern.

Be it known that I, ANTHONY GEoRoE MALDON MICHELL, a subject of the King of Great Britain, residing at No. 450 Collins Street, Melbourne, in the State of Victoria, Australia, consulting engineer, have invented certain new and useful Improvements in echanismf for the Interconversion of Reciprocating and Rotary Motion, of which the I following is a Specification.

The object of this invention is means of obtaining harmonic reciprocating h motion from uniform rotary motion or vice versa, applicable to steam and other heat engines, compressors for air and gas, a nd pumps, as well as to other machines in whlch the interconversion of these two types of motion is required.

The invention consists essentially in the combination ofa reciprocating element or elements with a rotating drive-plate, or swash-plate, and one or more slippers of special construction as hereinafter described orming connecting elements between the said reciprocating and rotary elements.

The employment of a swash plate or driveplate in mechanism for the purpose stated is well known and it has been customary to employ wheels or 'rollers to make contact with a minimum of friction between the reciprocating element and the drive-plate.

ore recently ball races have been employed for effecting the connectionstated and 1t has also been proposed to use slide blocks having plane surfaces making lubricated contact with the drive-plate and rotating.

about axes parallel to the line of motion of the reciprocating element. Such devices, however, have not proved suitable for operationwith intense pressures and high speeds, and consequently although mechanism of this class has been successfully employed for the operation of hydraulic pumps and motors, it has not hitherto been suitable for use in conjunction with engines and compressors.

The accompanying drawings illustrate a practical and thepreferred form of driveplate mechanism according tothisinvention,

and its application to a reciprocating engine.

Figs. 1, 2 and 3 parts of the invention as applied to a doubleacting piston Fig. 1 beingea longitudinal section through a cyhnder and 1ts piston arallel to the axis of rotation of the drive-pl ate; H l j Specification of LettersPatent.

an improved illustrate the essential axis of the piston as the ROTA RY MOTION.

Patented Mar. '7, 1922. Renewed April as, 1921. Serial No. 465,243.

Fig 2 a detail showing portion of the drlve-plateand the slippers in another posit1on; and 7 3 a plan view of one of the slippers;

Figs. 4, 5, 6, 7 and 8 illustrate of application of the invention plete machine, driven air compressor, Figs. 4 and 6 being axial sections respectively on the lines IVIV and 'VT-VI,- of Fig. 7, Fig. 5 an enlarged detail, Fig. 7 a cross-section on the line VII-QVII ofFigs. 4 and 6 with parts removed; and

F1g.- a detail view showing alternative constructions. I

In ig. l the drive-plate 1 is shown mounted obliquely on the rotating shaft 2 which revolves in the bearin s 3, 3, indicated by dotted lines. Oneof the working cylinders 4, 4 of an engine or compressor, whose axis is parallel to that of theshaft 2, is shown in longitudinal section together double-ended piston 5, 5, the working chambers 6, 6, of the cylinders being between the outside ends of the double piston 5, 5, and the closed'ends (not shown) of the cylinders.

The drive-plate 1 has the form of an to a comone method viz: a self-contained steamhaving trulyplane and parallel working surfaces 7, 7, The plate is rigidly mounted upon and revolves with the shaft 2.

The double-ended piston 5, 5, is'constructed in any usual manner suitable for the fluid with which it is to operate. The two ends of the double piston are rigidly connected together by the central bar' 8 which may have a projection 9 moving in a slot 10 formed either in the central portion of the double cylinder 6, 6, as shown, or in the frame of the engine so as to prevent the piston from rotating while allowing it to reciprocate parallel to its axis.

In order to transmit motion from the drive-plate 1 to the pistons 5, 5, or vice versa, two slipper blocks 11, 12 are arranged one on each side of the drive-plate 1, as shown, having plane working surfaces adapted to make lubricated contact with the corresponding plane surfaces 7, 7 of the drive-plate, and in order to enable the slippers 11-, 12 to follow the varying direction of inclination of the latter surfaces to the drive-plate rotates, they are furnished with universal joints'connecting them to the piston 5, 5. Theuni- V versal joints may conveniently take. the form slippers.

of spherical bosses 13,1 1 upon the slippers 11, 12, such bosses fitting into hollow spherical seats in the cups 15, 16 secured to the piston 5, 5. In Fig.- 1 the driveplate 1 a nd slippers 11, 12 are shown in such a posit on that the normal lines to their plane working surfaces have the maximum obliquity to the plane of the drawing. In Fig. 2 (drawn on the line Ill-J1 Fig. 1) a portion of the periphery of the drive-plate 1 and the slippers 11, 12 are shown-in the position corresponding to rotation through 90 from the position shown in Fig. 1, the normal lines to the working surfaces being then turned into the plane of the drawing. In order to adjust the working clearance which is necessary to allow eificient lubrication without undue play between the slippers 11, 12 and the working faces 7 7 of the drive-plate 1, the cups 15, 16 are constructed with fine threads and screwed into the pistons 5, 5, the adjustment being made permanent by means of set screws 17, 18 engaging with the peripheral notches 17 and 18 1n the cups 15. 16.

When the drive-plate 1 revolves invariably or usually in one direction, the slippers 11, 12 are preferably-made as shown in Fig. 3 with their bosses 13, 14 slightly behind the centres of the plane working surfaces of the The slippers will then operate so as to allow wedge-shaped-films of lubricant to be formed between their working surfaces and those of the drive-plate in a manner which is now well understood. For the same .purpose these slippers 11, 12 are also preferably constructed with relatively weak or flexible portions on the leading or on both the leading and trailing sides of the plate portions which make contact with the drive plate. In order to prevent the slippers 11, 12 from revolving about the axis of the piston 5, 5 as the drive-plate 1 revolves, the lat- I ter may be furnished with a projecting eccentric guide ring 19 shaped so as to fit approximately the inner edge 20 of the slipper 11, a similar guide ring being formed on the opposite side of the drive-plate 1 to form a similar guide for the slipper 12.

Alternatively to the construction of the slippers with spherical bosses fitting in concave seats attached to the pistons as above described, the pistons may be fitted with spherical projections fitting in concave seats in the slippers. Or the slippers and pistons may be connected by universal joints of other suitable types as, for instance, with the well known Hookes or Cardans joints, the essential purpose being to allowthe slippers to change the inclination of their work ing faces in every direction while maintaining the perpendicular distance between those working faces constant, or approximately constant.

In the example of the application of the invention illustrated in Figs. 1, 5, 6 and 7, a single-acting steam cylinder 6 and single acting compressor cylinder 6 are arranged in axial alignment and opposed to one another, four such pairs of cylinders being set symmetrically around the circumference of the machine as shown in Flg. 7. In each pair of cylinders a double piston, consistlng of a steam end 5 and an air end 5 connected by a central bar 8 is arranged substantially as already described'in connection with Figs. 1"and 2. The steam and air ends of the double piston are shown in the drawings of equal diameters but may be of different diameters adapted to the working pressures of the two fluids. Each double piston is provided with slipper blocks 11, 12 as already described, making working contact.

with a drive-plate 1 rigidly mounted on the. shaft 2 which extends through the whole length of the combined machine being mounted in bearings 21,22.

The drive-plate 1 is preferably constructed with a cylindrical boss 1*, integral with a plate-portion having the form of an oblique slice of a cylinder, and thrust rings 21*, 22 are interposed between the boss 1 and the bearings 21 and 22 to take any unbalanced axial force acting on the drive-plate.

Air enters the compressor cylinder 6 during the forward movement of the piston 5 through the open end 23 of the end cover 2 1 being admitted through the port 25 of the rotating valve 26 mounted on the shaft 2 when such port registers witheither of the four, admission ports 27 in the plate 28 which covers the otherwise open ends of the air cylinders 6*. On the return strokes of the pistons 5 compressed air is delivered through the same ports 27 and the port 30 of the rotating valve 26 into the annular chamber 31 in the (and cover 24 from which it is discharged through the pipe branch 31 (Fig. 6). To minimize clearance the pistons 5 are furnished with projections 29, approximately fitting the ports 27.

The cylinders 6 may be formed as liners, as shown, being inserted in the common casing 32', and may be surrounded by a waterjacket 33, for cooling purposes.

A similar casing 32, which may be bolted to the casing 32 as shown, on the line VII-VII, contains the steam cylinders 6, also formed as liners. The steam ends of "these cylinders are controlled by a rotating through a ring of ports 40 into an annular exhaust steam chamber 41 formed in the casing 32 and connected with the exhaust branch42 (Figs. 6 and 7).

The drive-plate 1 is enclosed in a central chamber 43 formed by the open inner ends of the casings 32 and 32 and is provided with means for forced lubrication from the oil pump 44 (Fig. 7) which delivers jets of oil through the passages 45, 45 bearing chambers 46 and nozzles 47 against the central portions of the plate 1, from which the oil is thrown outwardly by centrifugal force over the working surfaces on which the slipper blocks 11 and 12 make contact, and t ence returns to the suction branch 45 on the pump 44 in the lower part of the chamber 43 (Figs. 6 and 7). The'pump 44, may be driven through a spindle 48 and gear wheels 49, 50, from a piston 51 mounted on the main shaft 2. In order to prevent the slippers 11 from rotating about their axial centre-lines the means shown in Fig. 5 may be employed as alternatives to the projection 9 on bar 8, and rings 19 on drive-plate 1, as shown in Fig. 1. As Sb 5 rotation of the pistons 5, 5 is restrained by the bar 8 which consists of the bridge portion of the yoke piece 52 to which are screwed the said pistons 5, 5 and the cups 15, and the bar 8 is slotted at 53 so as to be guided longitudinally by the stud piece 54 fixed to the casing 32*, and engaging with the slot 53. A. ball-ended projection 55 from the slipper 11, also engages with the slot 53, and the slipper 11 is thus prevented from revolving though free to oscillate according to the varying direction of inclination of its surface to contact-with the plate 1 n engine constructed as herein described, with either three, four (as shown), or any greater number of pistons spaced equidistantly around the circumference of the driveplate, admits of perfect dynamic balance in all directions so as to communicate no vibration to its foundation, provided that the masses of the drive-plate and reciprocating pistons are correctly adjusted. For this purpose it is necessary that all the pistons, if equidistant, from the axis, shall be of equal mass, and that the mass of that portion of the drive-plate outside the boss which portion may be regarded as an oblique slice of a cylinder is determined by the algebraical formula A2 R r in which M is the mass'of the drive plate; n the number and mthe mass of each of the pistons with its attachment; R the radius of the outer surface of the drive-plate measaxis; 1- the radius of the boss of the drive-plate; and A the distance between the axis of the drive-plate own in Figs. 4 and J and 7.

and that of one of the pistons. The rotary valves, and other rotating parts, are independently balanced in the usual manner.

It is to be understood that the invention is not limited to the use of one or more double-ended pistons as described above, but that the construction which is the essence of the invention can be employed with a singleslipper, or with a single-ended piston having an extension to the opposite side of the drive-plate from the piston for the purpose of carrying a second slipper. These constructions are illustrated in Fig. 8 in which the single-ended piston 56 reciprocates in the cylinder 57, and is fitted with a slipper ll co-acting with a drive-plate 1 as already described. A yoke piece 58 attached to the cylinder 57 is slot- 32 as already described. In order to assist the piston 56 in making its return stroke a compression spring 59 may be inserted between it and the closed end 60 of the cylinder positively attached to Hookes or Cardan joint dicated.

It will also be understood that for special purposes the essential features of the invention may be applied to a'swash-plate having two plane, but not parallel, working faces in conjunction with single-ended pistons'as above described in connection with Fig.8 of which one or more are fitted with slippers co-acting with one working face, while another or others co-act with the other Working face of the swash-plate. By this means the single-acting pistons on one side of the drive plate have working strokes of a certain length, while the strokes of those on the other side have a different length.

y an alternative arrangement, the spring being omitted, the yoke piece 58 may be extended, as shown in dotted lines in Fig. 8, and arranged to carry a second slipper 12 (also dotted in Fig. 8) on the opposite side of the drive-plate 11, the action of the two slippers be1ng then precisely as already d in connection with. Figs. 4, 5, 6

the piston by a as hereinbefore in- It will further be understood thatthe details of construction may be modified for the use of the mechanism as in conjunction with a steam or internal combustion engine, pump, or compressor whether double-acting or single-acting, instead of as a combined engine and compressor as. above described. For uses in conjunction withthese machines other than those last mentioned the shaft 2 would be extended outside the casing as incable element, a universal dicated at 2', Figs. 4 and 6 and would be fitted with a coupling, pulley, or the like by which the power developed by, or applied to, the drive plate 1, would be transm1tted.

I claim:

1. In mechanism of the character described, the combination of a swash plate, a reciprocable element, and a slipper of the oil film lubricating type quaqua-versally articulated to said reciprocable element so as to permit the working surface of said plate and said slipper to co-act.

2. Mechanism for the purpose stated, comprising a rotary swash plate, a reciprocable element, a connection between said element and the swash plate embodying a slipper having a working working face of the swash plate the slipper being non-rotatable about an axis parallel to the direction of movement of the reciprojoint connecting the slipper with the reciprocable. element, and means for maintaining the slipper in cooperative working relation with the work ing face of the swash plate.

3. Mechanism for the purpose stated, comprising a rotary swash plate having opposite truly plane working faces disposed obliquely relatively to the axis ofrevolution of the swash plate, a reciprocable element, and a pair of plane surfaced slippers having articulated connections with said reciprocable element and means for preventing rotation of the slipper about an axis parallel to the direction of movement of the reciprocable element, said slippers bearing respectively on the opposite faces of the swash plate.

4. In mechanism for the purposestated, the combination with a swash plate having two plane and parallel working faces, of a reciprocable element having a pair of opposed slippers, having plane working faces cooperating with the respective working faces at opposite sides of the swash plate, each slipper being capable of articulated movement but non-rotatable relatively to the reciprocable direction of movement of the element while maintaining the perpendicular distance between their working faces substantially constant.

5. Mechanism for the purpose stated consisting of the combination with a swashplate, of reciprocable elements disposed symmetrically about said plate and effecting dynamic balance therewith, and a pair face to cooperate with a of plane surfaced articulated connecting slippers between each of saidelements and the swash plate, said slippers having means for preventing rotation thereof about an axis parallel to the direction of movement of said reciprocable elements.

6. In mechanism of the character described, the combination of a rotary swash plate having a plane working surface, a plane surfaced slipper cooperative therewith, a reciprocable element, a universal joint connecting the slipper to the reciprocable element, and means for holding said slipper from rotation relatively to the reciprocable element about an axis parallel to the direction of movement of said element.

7. In mechanism of the character described, the combination with a swash plate, a reciprocable element, a plane surfaced slipper cooperative with the swash plate and having an articulated connection with said reciprocable element, and means for restraining rotation of the slipper element relatively to the reciprocable element but permitting reciprocation of the latter.

8. In mechanism for the purpose stated, a casing containing the swash plate with means including a pump driven from the shaft of the latter and jets directed toward the swash plate for effecting forced feed lubrication to the working faces of the same.

9. In mechanism for the purpose stated, in combination, a swash plate, a reciprocable element comprising a piston carrying a slipper element articularly connected thereto at a point off-set in rear of the leading end of the slipper element to produce an interposed wedge shaped lubricant film connection between said plate and the slipper element and means for projecting a lubricant against the working face of the swash plate.

10. In mechanism for the purpose stated, a swash plate, reciprocable elements symmetrically balanced about a swash plate having truly plane working faces, said elements comprising pistons each carrying an articulated slipper arranged to effect lubricated contact with said working surfaces, said pistons and slippers being restrained from rotation, and means driven from the shaft of said plate for effecting forced lubrication to said working faces.

In testimony whereof I have hereunto set my hand.

ANTHONY GEORGE MALDON MICHELL. 

